Rolling element bearings, often used in rotor bearing systems of gas turbine engines for supporting rotating shafts, may be subjected to cyclical high loading forces, which may result in failure of the rolling element bearings. A primary failure mode is bearing spall evidenced by the release of particles from the failed rolling element bearing into the lubricating system. Conventional methods for detecting spall initiation in a rolling element bearing include detection of the presence of particles by an oil debris monitoring system. As not every spall progresses to failure within an expected period of time, the detection of spall initiation cannot be a predictor of how far along the rolling element bearing is in the failure progression process and when the imbalance response will occur with impending failure.